Animation system for a robot comprising a set of movable parts

ABSTRACT

The object of the invention is to make the movable parts of a robot reproduce the movement of the movable parts of an animated object, via the transmission of movement parameters to the robot in a primary signal PS. The primary signal PS comprises sets of parameters associated with the movable parts of the animated object, the sets of parameters being inserted in said primary signal according to a hierarchical graph structure reflecting the structure of the movable parts of said animated object. The movable parts of the robot reproduce the movement characterized by the movement parameters comprised in the sets of parameters which are associated with them. Use: An animation system for a robot.

The invention relates to an animation system for animating a robotcomprising a set of movable parts.

The invention has many applications in communication systems where themovement of an object or a person must be reproduced by a distant robot,in the context of industrial or domestic applications.

The use of robots is known in industrial environments for performing aset of complex repetitive tasks. The use of robots is also known in thecontext of domestic applications, in particular as a “helper robot”.

The Japanese patent No. P2001-96481A describes an animation system for arobot and a robot taking the appearance of a dog, said robot comprisingmeans for reproducing an action sent in the form of a control signalfrom a transmitter of the computer or remote control type. The robot isprovided with movable parts for reproducing said action, for example anaction corresponding to a movement of the feet or head.

The robot known from the document of the prior art is provided with asignal processor and a memory of the ROM type for storing a set ofprograms and parameters enabling the robot to reproduce a given seriesof actions. The robot is also in a position to interrupt an actioncurrently being executed if a control signal received reflects the factthat another action to be performed must be reproduced.

The animation system and the robot known from the document of the priorart have a certain number of limitations.

The behavior of the robot described by the document of the state of theart is modified by the sending of a control signal enabling actuators tomake the movable parts of the robot reproduce an action, in particular amovement action.

Since the behavior of the robot is mainly determined by a set ofprograms and parameters previously stored in memory, a control signalreceived by the robot can only partially modify the behavior of therobot. Because of this largely predetermined behavior, the robot knownfrom the document of the state of the art is limited in its behavior.

Accepting the eventuality that the programs and parameters stored inmemory are changed from time to time in order to change the overallbehavior of the robot, because of the large volume of data to be loaded,such an operation would require a significant amount of time because ofthe small bandwidth of the communication channel between the robot andthe transmitting system. In addition to the lack of flexibility, such anoperation would be difficult for a user to perform.

From the point of view of hardware resources, the robot known from thedocument of the state of the art requires a memory of large capacity forstoring the programs and action parameters, which results in anexpensive product.

One object of the invention is to make the movable parts of a robotreproduce the movement of the movable parts of an animated object, viathe transmission of movement parameters to the robot in a primarysignal, conferring flexibility of use and leading to an economicalsolution.

The invention relates to an animation system for a robot comprising:

-   -   a) a transmitter comprising:        -   means for creating a primary signal comprising sets of            parameters for describing the movement of a set of movable            parts of an animated object, a set of parameters comprising:            -   aa) an identification parameter for associating a                movable part with the set of parameters in question;    -   bb) movement parameters for describing the movement of the        movable part associated with the set of parameters,        -   transmission means for transmitting said primary signal,    -   b) a robot comprising:        -   reception means for receiving said primary signal,        -   movable parts able to be moved by control signals,        -   processing means for successively processing the sets of            parameters comprised in the primary signal received, said            processing means comprising:            -   aa) association means for, using the identification                parameter, associating a movable part of the robot with                the set of parameters,            -   bb) generation means for, using the movement parameters,                generating said control signals to the movable part                associated with the set of parameters, for the purpose                of making said associated movable part reproduce the                movement characterized by said movement parameters.

The invention proposes to code said primary signal transmitted to therobot according to a syntax dedicated to describing and transmittingcharacteristics of an animated object.

A coding syntax for describing the characteristics of an object in ascene is known from the standard bearing the reference MPEG-4 ISO/IEC14496-1 and MPEG-4 ISO/IEC 14496-2. This coding syntax is peculiar tothe normative functionality bearing the name MPEG-4 BIFS (from theEnglish “BInary Format for Scene description”). According to thisfunctionality, with a scene coded according to the MPEG-4 standard andcomprising multimedia scene elements (of the audio, text, graphical,video etc type), there is associated a data signal coded according tothe requirements of the MPEG-4 BIFS functionality describing theparameters of said scene elements. In particular, the descriptionparameters make it possible to describe animation characteristics foranimated objects with regard to their shape and spatio-temporalpositioning in said multimedia scene. The animation parameters of thescene elements are coded according to the coding syntax of the MPEG-4BIFS Anim functionality, whilst the parameters for updating the sceneelements are coded according to the coding syntax of the MPEG-4 BIFSUpdate functionality.

This movement parameter coding mode is advantageously used in thepresent invention for transmitting to a robot the movement parametersfor the movable parts of an animated object for the purpose of makingthe movable parts of a robot reproduce the movement characterized bysaid parameters. “Animated object” means a physical object, a virtualobject, a person or an animal. In this way the robot is in a position toreproduce the movements of the animated object.

For each movable part of the animated object, the movement parametersare inserted in a set of parameters, normally referred to as a “node”according to the MPEG-4 BIFS functionality, said set of parameters beingidentified so as to establish a correspondence at the robot between theset of parameters and a movable part of the robot. The sets ofparameters are arranged so as to form a graph with a hierarchicalstructure reflecting the structure and arrangement of the movable partsof the animated object with respect to one another.

A set of parameters comprises the movement parameters for describing themovement of the movable part of the animated object which corresponds toit, for example priorities for describing the spatial position of themovable part by means of coordinates in an orthonormal reference frame,by means of polar coordinates, or by means of a parameterizedtransformation of the rotation/translation type.

Using such a coding mode for sending movement parameters to the robothas the advantage of reducing the volume of the information to betransmitted to the robot since the MPEG-4 BIFS functionality makesprovision on the one hand for sending the animation parameters accordingto a differential mode, and on the other hand provides for thecompression of the signal by a quantization mechanism. In this way, onlya connection with a small bandwidth is necessary for transmitting themovement parameters to the robot.

Another advantage to the use of the MPEG-4 BIFS functionality is to beable to transmit to the robot a continuous flow of movement parametersin the primary signal, a transmission mode known by the term“streaming”. In this way, the robot does not need to first load aminimum set of movement parameters for its functioning. The robottherefore executes in real or pseudo-real time the movementcharacterized by the movement parameters comprised in said primarysignal. Consequently a robot according to the invention is no longerobliged to have available large memory resources, which leads to aneconomical solution.

Finally, the use of the MPEG-4 BIFS functionality makes the coding ofthe primary signal transmitted to the robot normative, which on the onehand facilitates the control of a plurality of robots by the samecontrol signal and on the other hand facilitates the exchange ofmovement parameters between a group of robots.

According to a particular embodiment, the system described abovecomprises movement capture means for generating movement parameterscharacterizing the movement of each movable part of the animated object.

This application makes it possible to make the robot reproduce themovements of the animated object. In particular, the animated objectcorresponds to a person equipped with movement sensors on his variouslimbs. In this case, the movement parameters of the various limbs of theperson are captured and inserted in the primary signal. The primarysignal thus created is transmitted to a robot comprising movable partsable to reproduce the movements of said limbs. By means of anassociation mechanism, each set of parameters received by the robot isassociated with a movable part of the robot reproducing the movementcharacterized by the movement parameters comprised in said set ofparameters.

The purpose of such an application is to reproduce at a user the actualmovements of a distant person so as to simulate his physical presence tothe user.

According to a particular embodiment, the animation system comprisesaudio coding means for coding an audio signal transmitted by saidanimated object, in order to generate an audio signal transmitted withsaid primary signal by said transmission means, said robot comprisingmeans for decoding and reproducing said audio signal.

In addition to the capture of the movement parameters, this embodimentmakes it possible, via audio sensors, to make the robot reproduce theaudio signal transmitted by the animated object, that is to say thespeech signal if it is a case of a person. Thus the audible expressionof the robot is merged with that of the distant person. For the purposeof reducing the volume of information, the audio signal isadvantageously coded by an audio coder situated in said transmitterbefore being transmitted.

This application advantageously replaces an application of the videoconference type. This is because, rather than displaying the distantperson on an audio/video display, the distant person is actuallyrepresented by the robot, which is in a position to reproduce theactions and the speech signal of the distant person.

The advantage of such an application is to transmit only compactinformation on the communication channels (the primary signal and audiosignal), unlike an application of the video conference type (for exampleaccording to the standard H.324) requiring the sending of videoinformation of good visual quality but at a high rate, or with a lowvideo rate but low visual quality.

This application can be used in the context of distance learning duringwhich the movements of a teacher distant with respect to a student arereproduced by a robot situated close to the student.

This application can be used in the context of a surgical operation at adistance for reproducing the actions of a surgeon distant from thepatient, the patient then being operated on by the robot.

This application can be used for enabling a deaf person to correspondwith a distant correspondent if the movement of the hands and mouth ofthis correspondent are reproduced by a robot situated close to the deafperson.

The invention also relates to an animation system for a robotcomprising:

-   -   a) a receiver for receiving a multimedia data signal composed of        scene elements, associated with a scene description signal for        describing said scene elements by means of description        parameters, said multimedia data signal comprising an animated        scene element comprising a set of movable parts, said scene        description signal comprising sets of parameters for describing        the movement of said movable parts, the sets of parameters        comprising:        -   aa) an identification parameter for associating a movable            part with the set of parameters in question,        -   bb) movement parameters for describing the movement of the            movable part associated with the set of parameters,    -   said receiver comprising:        -   extraction means for extracting from said scene description            signal the movement parameters of said animated object, and            generating a primary signal comprising said movement            parameters,        -   transmission means for transmitting said primary signal to            the robot;    -   b) a robot comprising:        -   reception means for receiving said primary signal,        -   movable parts able to be moved by control signals,        -   processing means for successively processing the sets of            parameters comprised in the primary signal received, said            processing means comprising:            -   aa) association means for, using the identification                parameter, associating a movable part of the robot with                the set of parameters,            -   bb) generation means for, using the movement parameters,                generating said control signals to the movable part                associated with the set of parameters, for the purpose                of making said associated movable part reproduce the                movement characterized by said movement parameters.

This application enables a robot to reproduce movements of an animatedobject of the scene element type (for example an avatar or a person),the animated scene element in particular forming part of a multimediascene coded according to the MPEG-4 standard. In order to generate theprimary signal transmitted to the robot, only the movement parameters ofthe animated scene element are extracted from the scene descriptionsignal by the receiver.

According to an additional characteristic, the receiver comprises scenecomposition means for generating a scene signal from the multimedia datasignal and the scene description signal, the content of said scenesignal being intended to be played by display and listening means.

The movements of the animated scene element being reproduced by therobot situated alongside the display means, the display of the contentof the multimedia scene is made more attractive and lively.

The multimedia data signal associated with the scene description signalcan for example be delivered by a television program supplier(broadcaster) or by a network game device. By choosing to make the robotreproduce the movements of an animated scene element forming part ofthis multimedia scene, this application affords greater “immersion” inthe multimedia scene content.

According to an additional characteristic, the robot comprisesmodification means for modifying the sets of parameters included in theprimary signal received.

This characteristic makes it possible to adapt the sets of parametersincluded in the primary signal to the capabilities of the robot. Thus,if movement parameters are such that the capabilities of the robot donot make it possible to reproduce the corresponding movement, the valueof the movement parameters included in said sets of parameters aremodified, or even omitted.

According to an additional characteristic, the robot comprises:

-   -   voice recognition means for an external audio signal for        generating a voice parameter,    -   matching means for matching said voice parameter with additional        movement parameters characterizing the movement of one or more        movable parts of the robot, said generation means generating a        control signal from said additional movement parameters.

This additional characteristic enables a user to interact with themovements of the robot by voice.

According to an additional characteristic, the robot comprises means forretransmitting said primary signal.

This characteristic makes it possible to transmit the content of theprimary signal to a set of robots so that the movements characterized bythe sets of parameters contained in said primary signal aresimultaneously reproduced by this set of robots.

The invention also relates to a robot as described in the aboveapplications and comprising:

-   -   reception means for receiving a primary signal, said primary        signal comprising sets of parameters for describing the movement        of a set of movable parts of an animated object, a set of        parameters comprising:        -   aa) an identification parameter for associating a movable            part with the set of parameters in question,        -   bb) movement parameters for describing the movement of the            movable part associated with the set of parameters,    -   movable parts able to be moved by control signals,    -   processing means for successively processing the sets of        parameters included in the primary signal received, said        processing means comprising:        -   aa) association means for, using the identification            parameter, associating a movable part of the robot with the            set of parameters,        -   bb) generation means for, using the movement parameters,            generating said control signals to the movable part            associated with the set of parameters, for the purpose of            making said associated movable part reproduce the movement            characterized by said movement parameters.

The invention also relates to a signal coded according to the codingsyntax of the MPEG-4 BIFS functionality for controlling the movement ofthe movable parts of a robot, said coded signal comprising sets ofparameters, a set of parameters comprising an identification parameterfor associating a movable part with a set of parameters in question andmovement parameters for describing the movement which said movable partis to be made to reproduce.

The invention will be further described with reference to examples ofembodiments shown in the drawings to which, however, the invention isnot restricted.

FIG. 1 describes schematically an animation system for a robot accordingto the invention,

FIG. 2 describes a first application of an animation system for a robotaccording to the invention,

FIG. 3 describes a second application of an animation system for a robotaccording to the invention.

FIG. 1 describes schematically an animation system for a robot accordingto the invention comprising a transmitter E for transmitting a primarysignal PS to a robot R. The purpose of the transmission of the primarysignal PS to the robot R is to make the robot R reproduce the movementsof an animated object O.

The animated object O resembles here a person comprising a set ofmovable parts 101-112) (body 101, head 102, mouth 103, eyes 104, leftarm 105, left hand 106, right arm 107, right hand 108, left leg 109,left foot 110, right leg 111, right foot 112). The movable parts form ahierarchical structure graph O-SG for describing the arrangement of themovable parts with respect to one another.

A movable part is described by a set of parameters comprising:

-   -   an identification parameter for associating the movable part        with the set of parameters in question. For example, the        identification parameter may correspond to a single numerical        value.    -   movement parameters for describing the movement of the movable        part associated with the set of parameters. For example, the        movement can be described by spatial coordinates of one or more        points defining the movable part, by a transformation of the        rotation type characterized by a center and an angle, or by a        translation characterized by a vector.

The transmitter E comprises means for creating the primary signal PSfrom the movement parameters of each of the movable parts 101-112. Theprimary signal PS is a signal coded according to the syntax of theMPEG-4 BIFS functionality, in which each set of parameters is consideredto be a node within the meaning of the MPEG-4 BIFS functionality, ormore precisely as an upper hierarchy node (also referred to as a “parentnode”) if other nodes depend on it, or as a lower hierarchy node (alsoreferred to as a “child node”) if it depends on other nodes. The signalPS therefore consists of the coding of the hierarchical structure of theanimated object O by arranging the sets of parameters according to thisstructure.

Through this hierarchical structure, a movement allocated to an upperhierarchy movable part is also applied to the lower hierarchy movableparts. For example, the movement of the movable part 102 is also appliedto the parts 103 and 104. Likewise, the movement parameters of themovable part 105 are also applied to the part 106.

The signal PS is transmitted by transmission means included in thetransmitter E to a robot R comprising a set of movable parts 101′-112′for reproducing the movement of the movable parts of the animated objectO.

After reception by the robot of the primary signal PS comprising thesets of parameters describing the movement of the movable parts of theanimated object O, association means associate each movable part of therobot with a set of parameters. This association is made using theidentification parameter contained in each set of parameters. Thus themovable part 101′ is associated with a set of parameters of the movablepart 101, the movable part 102′ is associated with a set of parametersof the movable part 102, etc.

The association means make it possible to generate a hierarchicalstructure graph R-SG for describing the arrangement of the movable parts101′-112′ with respect to one another. The movable parts of the robot Rbeing similar in their structure to the movable parts of the animatedobject O, the structure and movement of the movable parts 101-112 arerespectively reproduced by the movable parts 101′-112′. The graph R-SGis identical to the graph O-SG.

The movable parts of the robot R are moved by control signals applied tomechanical actuators, not shown here. The control signals applied to theactuators are generated by generation means for the purpose of makingthe associated movable part reproduce the movement characterized by themovement parameters contained in each set of parameters 101′-112′. Thesegeneration means consist of transcribing the movement parameters into asignal which can be used by said actuators. For example, the generationmeans transcribe the movement parameters into an electrical or pneumaticsignal enabling the actuator to effect the movement to the movable part.

FIG. 2 describes a first application of an animation system according tothe invention. This application comprises means of sensing the movementof the movable parts of a person O. These movement sensing meanscomprise movement sensors 201 disposed on each of the movable partswhose movement is to be reproduced by the robot R. These sensors 201deliver a set of signals 202 containing a physical quantity reflectingthe movement of each of the movable parts. These signals 202 aredelivered to processing means 203 for transforming the physical quantityof each signal into movement parameters 204 sent to means of creating agraph structure SGC. Using the parameters 204, the means SGC create agraph structure of the same type as the structure O-SG described in FIG.1, following the structural hierarchy of the movable parts of theanimated object O. The means SGC deliver the primary signal to be sentto the robot R.

Such an application can also comprise audio recording means 205 forpicking up an audio signal 206 transmitted by the person O. The signal206 is advantageously coded by an audio coder AC comprised in thetransmitter E, for example a coder according to the MP3 standard makingit possible to reduce the volume of the audio data to be transmitted.

The signals PS and 207 are transmitted to the robot R. For this purpose,they can be coded in advance by means TC according to varioustransportation protocols. For example, these signals can be inserted inan MPEG-2 transportation flow by a multiplexer before being transmittedpacket by packet over a network. These signals can also be coded bycoders according to the DECT, BLUETOOTH, GPRS or UMTS transportationprotocols before being sent over a wireless network.

The robot R comprises reception means for extracting the signals PS and207 coded according to one or more of the transportation protocolsmentioned above.

The robot R comprises an audio decoder for decoding the audio signal207, for example a decoder according to the MP3 standard. The audiosignal thus decoded is played by audio reproduction means of theloudspeaker type comprised in the robot.

To process the signal PS, the robot R comprises processing meansidentical to those described in FIG. 1.

This application makes it possible to advantageously replace anapplication of the video conferencing type using display means on ascreen. This is because, rather than displaying the distant person on anaudio/video display, the distant person is actually represented by therobot, which is in a position to reproduce the actions and the speechsignal of the distant person.

This application can be used in the context of distance learning duringwhich the movements of a teacher who is distant with respect to astudent are reproduced by a robot situated close to the student.

This application can be used in the context of a surgical operation at adistance for reproducing the actions of a surgeon distant from apatient, the patient then being operated on by the robot.

This application can be used to enable a deaf person to correspond witha distant correspondent if the movement of the hands and mouth of thiscorrespondent are reproduced by a robot situated close to the deafperson.

FIG. 3 describes a second application of an animation system accordingto the invention. This second application allows the reproduction by arobot R of the movements of an animated object O forming the sceneelement of a multimedia scene 301.

In addition to the scene element O, the multimedia scene 301 is composedof scene elements of the audio, text or graphical type, or a sceneelement 302 of the video type as in this example. The multimedia sceneis advantageously coded according to the MPEG-4 standard. Thus thespatio-temporal characteristics of the scene elements O and 302 aredescribed by description parameters comprised in a scene descriptionsignal coded according to the syntax of the MPEG-4 BIFS functionality.

The movable parts of the animated scene element O being identical tothose described in FIG. 1, the scene description signal constitutes agraph whose hierarchical structure is represented by the graph SG. Thisgraph comprises a first hierarchy for describing the spatio-temporalcharacteristics of the element 302 (characteristics not detailed in FIG.3) and a second hierarchy for describing the movement parameters of thescene element O. In an identical fashion to FIG. 1, the movement of eachmovable part 101-112 of the scene element O is described by a set ofparameters.

The scene elements are comprised in a multimedia data signal 303associated with the scene description signal 304. These signals are forexample delivered by a television program supplier.

The animation system according to the invention comprises a receiver305, for example of the set-top box type (or reception box), forreceiving the signals 303 and 304 via reception means which are notshown. The reception means correspond for example to a demodulator or toa demultiplexer.

The receiver 305 comprises extraction means 306 for extracting from saidscene description signal 304 the movement parameters of said animatedobject O, and generating a primary signal comprising said movementparameters. This extraction amounts to defining a new description signalin which only the hierarchical graph structure of the animated sceneelement O is kept, as illustrated by the graph R-SG.

The receiver 305 comprises transmission means 307 for transmitting saidprimary signal PS to the robot. These transmission means 307 effect acoding of the primary signal according to various transportationprotocols. For example, the primary signal can be inserted in an MPEG-2transportation flow by a multiplexer before being transmitted packet bypacket over a network. The primary signal can also be coded by a coderaccording to the DECT, BLUETOOTH, GPRS or UMTS transportation protocolsbefore being sent over a wireless network. For example, in the contextof a domestic application, the receiver 305 will for exampleadvantageously comprise a transmission module 307 for transmitting thesignal PS according to the BLUETOOTH transportation protocol.

The receiver 305 can also transmit an audio-type scene element to therobot R via said transmission means 307.

In order to process the signal PS, the robot R comprises processingmeans identical to those described in FIG. 1.

According to an additional characteristic, the receiver 305 comprisesscene composition means 308 for generating a scene signal 309 from themultimedia data signal 303 and the scene description signal 304, thecontent of said scene signal 309 being intended to be played by displayand listening means 310 of the television receiver type.

According to an additional characteristic, the robot R comprisesmodification means for modifying the sets of parameters included in thesignal PS. These modification means make it possible to adapt the setsof parameters comprised in the primary signal to the capabilities of therobot. Thus, if movement parameters are such that the capabilities ofthe robot do not make it possible to reproduce the correspondingmovement, said movement parameters are modified, or even omitted. Forexample, if a set of parameters associated with a movable part describesa translation defined by a unitary vector and its norm and the robot isnot in a position to reproduce a translation movement of such amagnitude, the movement parameters are for example initialized so as toprevent the robot from attempting to reproduce this movement, or thenorm of the unitary vector is reduced so as to enable the robot to beable to reproduce this translation movement partially.

According to an additional characteristic, the robot comprises:

-   -   means of voice recognition of an external audio signal in order        to generate a voice parameter,    -   matching means for matching said voice parameter with additional        movement parameters characterizing the movement of one or more        movable parts of the robot, said generation means generating a        control signal from said additional movement parameters.

This additional characteristic enables a user to interact with themovement of the movable parts of the robot by voice.

According to an additional characteristic, the robot comprises means ofretransmitting said primary signal, for example to other distant robotsor items of equipment requiring the movement parameters contained in theprimary signal. In this context, the robot R behaves like a transmittingterminal.

The invention has been described in the case of a coding of a primarysignal coded according to the syntax of the MPEG-4 BIFS functionality,in order to transmit movement parameters characterizing a movement whichis to be reproduced by the movable parts of a robot. Naturally, anyother coding syntax making it possible to describe movement parametersof an animated object forming part of an audio/visual scene could beused for coding such a primary signal without departing from the scopeof this invention.

The invention applies also to the transmission of a primary signalcomprising sets of movement parameters describing the animation of aface. In this case, a robot receiving such a primary signal would beprovided with a face comprising movable parts for reproducing such ananimation.

1. An animation system for a robot comprising: a) a transmittercomprising: means for creating a primary signal comprising sets ofparameters for describing the movement of a set of movable parts of ananimated object, a set of parameters comprising: aa) an identificationparameter for associating a movable part with the set of parameters inquestion, bb) movement parameters for describing the movement of themovable part associated with the set of parameters, transmission meansfor transmitting said primary signal, b) a robot comprising: receptionmeans for receiving said primary signal, movable parts able to be movedby control signals, processing means for successively processing thesets of parameters comprised in the primary signal received, saidprocessing means comprising: aa) association means for, using theidentification parameter, associating a movable part of the robot withthe set of parameters, bb) generation means for, using the movementparameters, generating said control signals to the movable partassociated with the set of parameters, for the purpose of making saidassociated movable part reproduce the movement characterized by saidmovement parameters.
 2. A system as claimed in claim 1, wherein saidcreation means comprise movement sensing means for generating movementparameters characterizing the movement of each movable part of theanimated object.
 3. A system as claimed in claim 2, comprising audiocoding means for coding an audio signal transmitted by said animatedobject, in order to generate an audio signal transmitted with saidprimary signal by said transmission means, said robot comprising meansfor decoding and reproducing said audio signal.
 4. An animation systemfor a robot comprising: a) a receiver for receiving a multimedia datasignal composed of scene elements, associated with a scene descriptionsignal for describing said scene elements by means of descriptionparameters, said multimedia data signal comprising an animated sceneelement comprising a set of movable parts, said scene description signalcomprising sets of parameters for describing the movement of saidmovable parts, the sets of parameters comprising: aa) an identificationparameter for associating a movable part with the set of parameters inquestion, bb) movement parameters for describing the movement of themovable part associated with the set of parameters, said receivercomprising: extraction means for extracting from said scene descriptionsignal the movement parameters of said animated object, and generating aprimary signal comprising said movement parameters, transmission meansfor transmitting said primary signal to the robot; b) a robotcomprising: reception means for receiving said primary signal, movableparts able to be moved by control signals, processing means forsuccessively processing the sets of parameters comprised in the primarysignal received, said processing means comprising: aa) association meansfor, using the identification parameter, associating a movable part ofthe robot with the set of parameters, bb) generation means for, usingthe movement parameters, generating said control signals to the movablepart associated with the set of parameters, for the purpose of makingsaid associated movable part reproduce the movement characterized bysaid movement parameters.
 5. A system as claimed in claim 4, wherein thereceiver comprises scene composition means for generating a scene signalfrom the multimedia data signal and the scene description signal, thecontent of said scene signal being intended to be played by display andlistening means.
 6. A system as claimed in claim 5, characterized inthat the robot comprises modification means for modifying the sets ofparameters comprised in the primary signal received.
 7. A system asclaimed in claim 3, characterized in that the robot comprises: voicerecognition means for an external audio signal for generating a voiceparameter, matching means for matching said voice parameter withadditional movement parameters characterizing the movement of one ormore movable parts of the robot, said generation means generating acontrol signal from said additional movement parameters.
 8. A system asclaimed in claim 7, characterized in that the robot comprises means forretransmitting said primary signal.
 9. A robot comprising: receptionmeans for receiving a primary signal, said primary signal comprisingsets of parameters for describing the movement of a set of movable partsof an animated object, a set of parameters comprising: aa) anidentification parameter for associating a movable part with the set ofparameters in question, bb) movement parameters for describing themovement of the movable part associated with the set of parameters,movable parts able to be moved by control signals, processing means forsuccessively processing the sets of parameters included in the primarysignal received, said processing means comprising: aa) association meansfor, using the identification parameter, associating a movable part ofthe robot with the set of parameters, bb) generation means for, usingthe movement parameters, generating said control signals to the movablepart associated with the set of parameters, for the purpose of makingsaid associated movable part reproduce the movement characterized bysaid movement parameters.
 10. A signal coded according to the codingsyntax of the MPEG-4 BIFS functionality for controlling the movement ofthe movable parts of a robot, said coded signal comprising sets ofparameters, a set of parameters comprising an identification parameterfor associating a movable part with the set of parameters in questionand movement parameters for describing the movement which said movablepart is to be made to reproduce.